[PATCH v3 06/12] cache-tree: simplify locking logic
- From
- Martin Ågren <martin.agren@gmail.com>
- Date
- Oct 6, 2017, 20:12 UTC
- Message-ID
- <2954e5ec4361c6932593663859aa437583edb500.1507320376.git.martin.agren@gmail.com>
- In-Reply-To
- <cover.1507320376.git.martin.agren@gmail.com>
After we have taken the lock using `LOCK_DIE_ON_ERROR`, we know that `newfd` is non-negative. So when we check for exactly that property before calling `write_locked_index()`, the outcome is guaranteed.
If we write and commit successfully, we set `newfd = -1`, so that we can later avoid calling `rollback_lock_file` on an already-committed lock. But we might just as well unconditionally call `rollback_lock_file()` -- it will be a no-op if we have already committed.
All in all, we use `newfd` as a bool and the only benefit we get from it is that we can avoid calling a no-op. Remove `newfd` so that we have one variable less to reason about.
Signed-off-by: Martin Ågren <martin.agren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com> --- cache-tree.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/cache-tree.c b/cache-tree.c index 71d092ed5..f646f5673 100644 --- a/cache-tree.c +++ b/cache-tree.c @@ -602,11 +602,11 @@ static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *pat int write_index_as_tree(unsigned char *sha1, struct index_state *index_state, const char *index_path, int flags, const char *prefix) { - int entries, was_valid, newfd; + int entries, was_valid; struct lock_file lock_file = LOCK_INIT; int ret = 0; - newfd = hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR); + hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR); entries = read_index_from(index_state, index_path); if (entries < 0) { @@ -625,10 +625,7 @@ int write_index_as_tree(unsigned char *sha1, struct index_state *index_state, co ret = WRITE_TREE_UNMERGED_INDEX; goto out; } - if (0 <= newfd) { - if (!write_locked_index(index_state, &lock_file, COMMIT_LOCK)) - newfd = -1; - } + write_locked_index(index_state, &lock_file, COMMIT_LOCK); /* Not being able to write is fine -- we are only interested * in updating the cache-tree part, and if the next caller * ends up using the old index with unupdated cache-tree part @@ -650,8 +647,7 @@ int write_index_as_tree(unsigned char *sha1, struct index_state *index_state, co hashcpy(sha1, index_state->cache_tree->oid.hash); out: - if (0 <= newfd) - rollback_lock_file(&lock_file); + rollback_lock_file(&lock_file); return ret; }
-- 2.15.0.rc0